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Miguel R. Lugo Ravikiran Ravulapalli Debajyoti Dutta 《Journal of biomolecular structure & dynamics》2016,34(12):2537-2560
C3larvin toxin is a new member of the C3 class of the mono-ADP-ribosyltransferase toxin family. The C3 toxins are known to covalently modify small G-proteins, e.g. RhoA, impairing their function, and serving as virulence factors for an offending pathogen. A full-length X-ray structure of C3larvin (2.3 Å) revealed that the characteristic mixed α/β fold consists of a central β-core flanked by two helical regions. Topologically, the protein can be separated into N and C lobes, each formed by a β-sheet and an α-motif, and connected by exposed loops involved in the recognition, binding, and catalysis of the toxin/enzyme, i.e. the ADP-ribosylation turn–turn and phosphate–nicotinamide PN loops. Herein, we provide two new C3larvin X-ray structures and present a systematic study of the toxin dynamics by first analyzing the experimental variability of the X-ray data-set followed by contrasting those results with theoretical predictions based on Elastic Network Models (GNM and ANM). We identify residues that participate in the stability of the N-lobe, putative hinges at loop residues, and energy-favored deformation vectors compatible with conformational changes of the key loops and 3D-subdomains (N/C-lobes), among the X-ray structures. We analyze a larger ensemble of known C3bot1 conformations and conclude that the characteristic ‘crab-claw’ movement may be driven by the main intrinsic modes of motion. Finally, via computational simulations, we identify harmonic and anharmonic fluctuations that might define the C3larvin ‘native state.’ Implications for docking protocols are derived. 相似文献
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Helen L. Henry Chhanda Dutta Noreen Cunningham Raymond Blanchard Robert Penny Chilung Tang Gail Marchetto Shu-Yin Chou 《The Journal of steroid biochemistry and molecular biology》1992,41(3-8)
The synthesis of 1,25(OH)2D3 is a critical control point in the regulation of calcium metabolism, and possibly in the growth and differentiation of a number of cell types. This paper reviews our current understanding of the regulation of this process at the cellular and molecular levels, with the emphasis on the mechanisms of feedback control 1,25(OH)2D3 itself, control of parathyroid hormone, the roles of cyclic AMP dependent protein kinase and protein kinase C, and the interaction between the various intracellular regulators of 1,25(OH)2D3 production. 相似文献
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Summary As a part of integrated study of makhana, the mineral contents of the plant parts and the fruits of makhana (Euryale ferox) have been presented here. It has been observed that the fruits were not only rich in minerals but also in protein. The plant
parts also contained high amounts of micronutrients. Its fruits are, therefore, a good supplement for minerals which are produced
from otherwise agriculturally waste (water-logged) areas. 相似文献
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Callus was successfully initiated on root, mesocotyl and leaf base segments of 3- to 4-day-old seedlings of ragi (Eleusine coracana Gaertn.). 2,4-D along with casein hydrolysate for Murashige and Skoog's basal medium was found to be most effective for callus initiation and maintenance. Mesocotyl and leaf base tissue derived calli gave shoot buds in medium in which the 2,4-D concentration was lowered. 相似文献
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R Rastogi S Sharma N Anand A Dutta N Fatma R K Chatterjee A B Sen 《Journal of helminthology》1984,58(3):251-254
The synthesis and filaricidal activity of 1-iso-butoxycarbonyl-4-methylpiperazine against Litomosoides carinii in Sigmodon hispidus and Dipetalonema viteae in Mastomys natalensis is reported. At an intraperitoneal or oral dose of 3 mg/kg given for 6 days, the compound removed 91% of the circulating microfilariae but had no effect on adult L. carinii. However, it killed all microfilariae and adults of D. viteae at a subcutaneous dose of 50 mg/kg given for 6 days. The compound also possessed chemoprophylactic activity against the larvae of L. carinii and D. viteae at a dose of 30 and 50 mg/kg respectively. 相似文献
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Detailed information was obtained regarding the partial structure of the lipopolysaccharide (LPS), containing glucose, glucuronic acid, 2-amino-2-deoxy-glucose, L-glycero-D-gluco-heptose, and small proportions of L-glycero-D-manno-heptose, mannose, and galactose, isolated from Vibrio cholera Ogawa G-2102. Structures of three oligosaccharides were determined. Results of deamination experiments established the sequence of the linkages between the amino sugar and heptose residues in the O-antigenic polysaccharide. 相似文献
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